The majority of surgical procedures rely upon various types of sutures for not only closing incisions, but also for connecting and/or supporting structures within the body. The use of sutures also usually requires the tying of one or more knots in order to secure the suture in place. There are many ways for tying sutures and will not be discussed here in detail to prevent obfuscation of the present invention. However, for exemplary purposes only, one known procedure is a “taut-line hitch” knot. The knot is formed in the loose ends of the suture at a location remote from the surgical site from which the suture ends emanate, and then the knot is run down the suture ends to the surgical site by pulling with a sawing motion on the appropriate suture ends. A significant drawback to this procedure is that as the appropriate suture end is pulled through the tissue in which the suture is implanted so as to run the knot down to the surgical site, the sawing motion imparted to the suture ends causes the latter to tend to cut and abrade the tissue.
An alternative procedure consists of forming a throw in the suture at a location remote from the surgical site from which the suture ends emanate, running the throw down the length of suture to the surgical site, forming a second throw in the suture at a location remote from the surgical site, running that throw down the length of suture to the surgical site so that it sits atop the first throw, and thereafter repeating the foregoing process as many times as necessary so as to form the desired knot at the surgical site. As used herein, a “turn” consists of two ends of suture which are looped over one another one or more times, a “throw” consists of one or more turns, and a “knot” consists of two or more throws laid on top of one another and tightened so as to lock the two strands of suture relative to one another.
After the knot is tied, the pair of suture tails extending from the knot normally must be cut. If the tails are cut too short or unevenly, the knot may become untied. Alternatively, if the tails are left too long, the suture tails may be irritating to the patient or become entangled with other structures. The term “suture tail” is meant to include any length of suture, whether or not it is extending from a knot.
The cutting of suture tails can often be accomplished merely by employing surgical scissors, particularly when the knot is located outside of the patient's body. Many times, however, the knot and accompanying suture tails are located within the patient's body, or within an orifice of the patient's body. For example, sutures may be tied within the abdomen or heart of a patient during a surgical procedure. In these instances, it may be difficult for medical personnel to safely employ standard surgical scissors to cut the sutures after tying. Thus, various types of suture-cutting devices have been developed which enable the medical personnel to cut the sutures in a location which normally would not be accessible to a pair of conventional scissors. These devices of the prior art suffer from many drawbacks, however, including the risk of the cutting blade inadvertently injuring the patient or physician or cutting the tissue or a blood vessel. In addition, vision is often impaired during these procedures, and thus it can be difficult for the medical personnel to insure that the suture tails are left at the proper length. Most of these devices are also unable to simultaneously cut both tails. Thus, a reliable suture cutting device is needed whereby a surgeon can rapidly and accurately trim back the strands from a knot.